Zirconium oxide ceramics flexural strength of 1000MPa, is the tallest of all-ceramic materials, more than most of the strength of dental alloy, known as "ceramic steel", but the fracture toughness value below 10 Mpa • M1/2, dental alloy in more than 40 Mpa • M1/2, that is all-ceramic materials have a high bending strength, but brittle high.